diff options
| -rw-r--r-- | fs/locks.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/fs/locks.c b/fs/locks.c index 941b7146b6be..71d847cbbb63 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -126,6 +126,7 @@ #include <linux/time.h> #include <linux/rcupdate.h> #include <linux/pid_namespace.h> +#include <linux/hashtable.h> #include <asm/uaccess.h> @@ -160,13 +161,21 @@ int lease_break_time = 45; static HLIST_HEAD(file_lock_list); /* - * The blocked_list is used to find POSIX lock loops for deadlock detection. - * Protected by file_lock_lock. + * The blocked_hash is used to find POSIX lock loops for deadlock detection. + * It is protected by file_lock_lock. + * + * We hash locks by lockowner in order to optimize searching for the lock a + * particular lockowner is waiting on. + * + * FIXME: make this value scale via some heuristic? We generally will want more + * buckets when we have more lockowners holding locks, but that's a little + * difficult to determine without knowing what the workload will look like. */ -static HLIST_HEAD(blocked_list); +#define BLOCKED_HASH_BITS 7 +static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); /* - * This lock protects the blocked_list, and the file_lock_list. Generally, if + * This lock protects the blocked_hash and the file_lock_list. Generally, if * you're accessing one of those lists, you want to be holding this lock. * * In addition, it also protects the fl->fl_block list, and the fl->fl_next @@ -515,13 +524,13 @@ locks_delete_global_locks(struct file_lock *fl) static inline void locks_insert_global_blocked(struct file_lock *waiter) { - hlist_add_head(&waiter->fl_link, &blocked_list); + hash_add(blocked_hash, &waiter->fl_link, (unsigned long)waiter->fl_owner); } static inline void locks_delete_global_blocked(struct file_lock *waiter) { - hlist_del_init(&waiter->fl_link); + hash_del(&waiter->fl_link); } /* Remove waiter from blocker's block list. @@ -748,7 +757,7 @@ static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) { struct file_lock *fl; - hlist_for_each_entry(fl, &blocked_list, fl_link) { + hash_for_each_possible(blocked_hash, fl, fl_link, (unsigned long)block_fl->fl_owner) { if (posix_same_owner(fl, block_fl)) return fl->fl_next; } @@ -884,7 +893,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str /* * New lock request. Walk all POSIX locks and look for conflicts. If * there are any, either return error or put the request on the - * blocker's list of waiters and the global blocked_list. + * blocker's list of waiters and the global blocked_hash. */ if (request->fl_type != F_UNLCK) { for_each_lock(inode, before) { |